A nonwoven fabric is a textile structure consisting of a mat of fibers held together with a bonding material. The fibers can be partially orientated or randomly distributed. A synthetic latex can be used as the binder for the fibers in nonwoven fabrics.
A number of methods have been developed for treating webs of fibers with a binder. Typically, a water-based emulsion binder system is used in which a thermoplastic or a thermosetting synthetic polymer latex is prepared and a loose web of fibers to be treated is immersed therein using special equipment, in view of the structural weakness of the web. The treated web is then dried and cured to effect proper bonding. Alternatively, an aqueous or a solvent solution binder system of a thermoplastic or thermosetting resin can be used to impregnate the web.
Still other methods include the application of thermoplastic or thermosetting resin powders to the fibers, before or after making a web of same, and passing the web through hot rolls or a hot press to bind the fibers together. Also, thermoplastic fibers having a softening point below that of the base fibers can be interspersed in a web of the latter and sufficient heat and pressure applied, such as by the use of heated rolls, to soften the thermoplastic fibers and bind the fiber network together.